update the cursor size while holding left and right keys
when i work i often have the panels hidden so i can see more of my picture, and i'll use the arrow keys to change the cursor size but you cannot see the size change until you let go so it's a bit of a guessing game as to how long to hold it to get it the correct size so if you could make it update in real time that'd be great.
another thing that is less needed but would be nice is have the cursor oval drawn in the current paint colour.
also the cursor could be a straight line in the size and direction of the brush rather than a crosshair when it's small as that'd be much more useful, the crosshair isn't much help other than for positioning as you can't see the size or direction of the brush.
i never knew i was so empty that i could be so full...